INTRODUCTIONThe purpose of this investigation was to identify an unknown bacteria. “At any time, millions of bacteria live around, on or inside us” (The Plague). The bacteria cannot be identified just by looking at it. Many bacteria have similar appearances when growing. “In most cases, detection relies on the reaction of an enzyme with a certain substrate” (Sigma-Aldrich). Identification is generally based on the results of the metabolic capabilities of the bacteria's cells. Some bacteria are harmless and part of our normal flora. While other bacteria are capable of causing illness or death. In order to determine what type of bacteria is present, a set of biochemical tests must be performed. With biochemical testing, the ability to identify the bacteria responsible for causing illnesses or conditions. Once this is determined, further testing can be done to find out which treatments would be most effective in eliminating the bacteria causing the illness. During the investigation, seven tests were used to determine the unknown bacteria known as Salmonella typhimurium. “Salmonella typhimurium is a genus of Gram-negative, non-lactose fermenting, medium-sized, rod-shaped bacteria, members of the family Enterobacteriaceae, most species having flagella and pili” (Medical Dictionary). This bacteria is known to cause food poisoning. These illnesses usually last 4 to 7 days. Treatments for diseases caused by this bacteria depend on the severity of symptoms, patient age and comorbidities.MATERIALS AND METHODSDuring this investigation to identify the unknown bacteria, seven different biochemical tests were performed. All biochemical tests were performed according to the Eastfield Microbiology Laboratory manual. As with...... middle of article...... health problems, the symptoms may be more serious. REFERENCESEastfield College Microbiology Laboratory. (2013). [Comparison table of biochemical test results]. Raw data not published. Eastfield College Microbiology Laboratory Manual, 1st edition, Oliver, TD (book must be purchased new from the Eastfield Bookstore and cannot be resold to the bookstore at the end of the semester), Kendall Hunt Publishing, 2013, Dubuque, IA. ISBN 9781465223784. Microbiology with Diseases by Body System (Hardcover) and Mastering Microbiology, 3rd Edition, Bauman, RW, Benjamin-Cummings Publishing Company, 2012, San Francisco, CA. ISBN 9780321716378. ORCefrey, Holly. The plague. New York: Rosen, 2001. Print. http://www.sigmaaldrich.com/analytical-chromatography/microbiology/identification-tests/reagents.html 2013 “Welcome to Microbugz”. Welcome to Microbugz. Linda Beaver and Mary Rutter, Internet. 2000